refactor(org-export): delete dead ox-texinfo block, relocate footnote setting

The ox-texinfo block could never run: :defer t with no autoload trigger,
and absent from the dolist that force-requires the other backends. So its
:config never fired, and Texinfo export was unavailable despite the
commentary advertising it. I deleted the block and dropped the Texinfo
line from the commentary. The commentary also claimed subtree default
scope while the code sets 'buffer, so I fixed that too.

I moved org-html-footnote-separator out of org-babel-config, where it sat
as a stray ox-html setting, into ox-html's own :config. ox-html loads
before any HTML export reads the value, so the timing is unchanged.

0 files changed, 0 insertions, 0 deletions